Ultraviolet treatment apparatus

ABSTRACT

A process module for treating a dielectric film and, in particular, a process module for exposing, for example, a low dielectric constant (low-k) dielectric film to ultraviolet (UV) radiation is described. The process module includes a process chamber, a substrate holder coupled to the process chamber and configured to support a substrate, and a radiation source coupled to the process chamber and configured to expose the dielectric film to electromagnetic (EM) radiation. The radiation source includes a UV source, wherein the UV source has a UV lamp, and a reflector for directing reflected UV radiation from the UV lamp to the substrate. The reflector has a dichroic reflector, and a non-absorbing reflector disposed between the UV lamp and the substrate, and configured to reflect UV radiation from the UV lamp towards the dichroic reflector, wherein the non-absorbing reflector substantially prevents direct UV radiation from the UV lamp to the substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 37 CFR §1.78(a)(4), this application claims the benefit ofand priority to U.S. Provisional application Ser. No. 61/318,719 filedon Mar. 29, 2010; the entire content of which is herein incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an apparatus for treating dielectric films,such as low dielectric constant (low-k) dielectric films.

2. Description of Related Art

As is known to those in the semiconductor art, interconnect delay is amajor limiting factor in the drive to improve the speed and performanceof integrated circuits (IC). One way to minimize interconnect delay isto reduce interconnect capacitance by using low dielectric constant(low-k) materials as the insulating dielectric for metal wires in the ICdevices. Thus, in recent years, low-k materials have been developed toreplace relatively high dielectric constant insulating materials, suchas silicon dioxide. In particular, low-k films are being utilized forinter-level and intra-level dielectric layers between metal wires insemiconductor devices. Additionally, in order to further reduce thedielectric constant of insulating materials, material films are formedwith pores, i.e., porous low-k dielectric films. Such low-k films can bedeposited by a spin-on dielectric (SOD) method similar to theapplication of photo-resist, or by chemical vapor deposition (CVD).Thus, the use of low-k materials is readily adaptable to existingsemiconductor manufacturing processes.

Low-k materials are less robust than more traditional silicon dioxide,and the mechanical strength deteriorates further with the introductionof porosity. The porous low-k films can easily be damaged during plasmaprocessing, thereby making desirable a mechanical strengthening process.It has been understood that enhancement of the material strength ofporous low-k dielectrics is essential for their successful integration.Aimed at mechanical strengthening, alternative curing techniques arebeing explored to make porous low-k films more robust and suitable forintegration.

The curing of a polymer includes a process whereby a thin filmdeposited, for example, using spin-on or vapor deposition (such aschemical vapor deposition CVD) techniques, is treated in order to causecross-linking within the film. During the curing process, free radicalpolymerization is understood to be the primary route for cross-linking.As polymer chains cross-link, mechanical properties, such as for examplethe Young's modulus, the film hardness, the fracture toughness and theinterfacial adhesion, are improved, thereby improving the fabricationrobustness of the low-k film.

As there are various strategies to forming porous dielectric films withultra low dielectric constant, the objectives of post-depositiontreatments (curing) may vary from film to film, including for examplethe removal of moisture, the removal of solvents, the burn-out ofporogens used to form the pores in the porous dielectric film, theimprovement of the mechanical properties for such films, and so on.

Low dielectric constant (low k) materials are conventionally thermallycured at a temperature in the range of 300 degrees C. to 400 degrees C.for CVD films. In some instances, furnace curing has been sufficient inproducing strong, dense low-k films with a dielectric constant greaterthan approximately 2.5. However, when processing porous dielectric films(such as ultra low-k films) with a high level of porosity, the degree ofcross-linking achievable with thermal treatment (or thermal curing) isno longer sufficient to produce films of adequate strength for a robustinterconnect structure.

During thermal curing, an appropriate amount of energy is delivered tothe dielectric film without damaging the dielectric film. Within thetemperature range of interest, however, only a small amount of freeradicals can be generated. Only a small amount of thermal energy canactually be absorbed in the low-k films to be cured due to the thermalenergy lost in the coupling of heat to the substrate and the heat lossin the ambient environment. Therefore, high temperatures and long curingtimes are required for typical low-k furnace curing. But even with ahigh thermal budget, the lack of initiator generation in the thermalcuring and the presence of a large amount of methyl termination in theas-deposited low-k film can make it very difficult to achieve thedesired degree of cross-linking.

SUMMARY OF THE INVENTION

The invention relates to an apparatus for treating dielectric films,such as low dielectric constant (low-k) dielectric films.

According to an embodiment, a process module for treating a substrate isdescribed. The process module includes a process chamber, a substrateholder coupled to the process chamber and configured to support asubstrate, and a radiation source coupled to the process chamber andconfigured to expose the dielectric film to electromagnetic (EM)radiation. The radiation source includes a UV source, wherein the UVsource has a UV lamp, and a reflector for directing reflected UVradiation from the UV lamp to the substrate. The reflector has adichroic reflector, and a non-absorbing reflector disposed between theUV lamp and the substrate, and configured to reflect UV radiation fromthe UV lamp towards the dichroic reflector, wherein the non-absorbingreflector substantially prevents direct UV radiation from the UV lamp tothe substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 illustrates a method of integrating a dielectric film on asubstrate according to an embodiment;

FIG. 2 illustrates a method of integrating a dielectric film on asubstrate according to another embodiment;

FIG. 3 illustrates a method of cleaning a substrate according to anembodiment;

FIGS. 4A and 4B provide a schematic illustration of a method and systemfor cleaning a substrate according to additional embodiments;

FIGS. 5A through 5D illustrate a method of cleaning a substrateaccording to yet additional embodiments;

FIG. 6 illustrates a side view schematic representation of an exemplarytransfer system for a treatment system according to an embodiment;

FIG. 7 illustrates a top view schematic representation of the transfersystem depicted in FIG. 6;

FIG. 8 illustrates a side view schematic representation of anotherexemplary transfer system for a treatment system according to anotherembodiment;

FIG. 9 illustrates a top view schematic representation of yet anotherexemplary transfer system for a treatment system according to anotherembodiment;

FIG. 10 is a schematic cross-sectional view of a process moduleaccording to another embodiment;

FIG. 11 is a schematic cross-sectional view of a process moduleaccording to another embodiment;

FIG. 12 is a schematic cross-sectional view of a process moduleaccording to another embodiment; and

FIG. 13 is a schematic cross-sectional view of a process moduleaccording to another embodiment.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Methods for integrating, patterning, treating, curing, and cleaningdielectric layers, including low-k dielectric films, on a substrateusing electromagnetic (EM) radiation are described in variousembodiments. One skilled in the relevant art will recognize that thevarious embodiments may be practiced without one or more of the specificdetails, or with other replacement and/or additional methods, materials,or components. In other instances, well-known structures, materials, oroperations are not shown or described in detail to avoid obscuringaspects of various embodiments of the invention. Similarly, for purposesof explanation, specific numbers, materials, and configurations are setforth in order to provide a thorough understanding of the invention.Nevertheless, the invention may be practiced without specific details.Furthermore, it is understood that the various embodiments shown in thefigures are illustrative representations and are not necessarily drawnto scale.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, material, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the invention, but do not denote that theyare present in every embodiment. Thus, the appearances of the phrases“in one embodiment” or “in an embodiment” in various places throughoutthis specification are not necessarily referring to the same embodimentof the invention. Furthermore, the particular features, structures,materials, or characteristics may be combined in any suitable manner inone or more embodiments. Various additional layers and/or structures maybe included and/or described features may be omitted in otherembodiments.

“Substrate” as used herein generically refers to the object beingprocessed in accordance with the invention. The substrate may includeany material portion or structure of a device, particularly asemiconductor or other electronics device, and may, for example, be abase substrate structure, such as a semiconductor wafer or a layer on oroverlying a base substrate structure such as a thin film. Thus,substrate is not intended to be limited to any particular basestructure, underlying layer or overlying layer, patterned orunpatterned, but rather, is contemplated to include any such layer orbase structure, and any combination of layers and/or base structures.The description below may reference particular types of substrates, butthis is for illustrative purposes only and not limitation.

The inventors recognized that alternative methods for treating asubstrate, and in particular, treating a substrate having a low-kdielectric film, address some of the deficiencies of conventional curingmethods, such as thermal curing, as well as conventional cleaningmethods, such as plasma ashing and wet cleaning. For instance,alternative methods for curing and cleaning such films are moreefficient in energy transfer, as compared to their conventionalcounterpart, and the higher energy levels found in the form of energeticparticles, such as accelerated electrons, ions, or neutrals, or in theform of energetic photons, can easily excite electrons in a low-kdielectric film, thus efficiently breaking chemical bonds anddissociating side groups. These alternative methods may facilitate thegeneration of cross-linking initiators (free radicals) and can improvethe energy transfer required in actual cross-linking. As a result, thedegree of cross-linking can be increased at a reduced thermal budget.

Additionally, the inventors have realized that, when film strengthbecomes a greater issue for the integration of low-k and ultra-low-k(ULK) dielectric films (dielectric constant less than approximately2.5), alternative methods for curing and cleaning such films may improvethe mechanical properties of such films. For example, electron beam(EB), ultraviolet (UV) radiation, infrared (IR) radiation and microwave(MW) radiation may be used to cure low-k films and ULK films in order toimprove mechanical strength, while not sacrificing the dielectricproperty and film hydrophobicity.

However, although EB, UV, IR and MW curing all have their own benefits,these techniques also have limitations. High energy curing sources suchas EB and UV can provide high energy levels to generate more than enoughcross-linking initiators (free radicals) for cross-linking, which leadsto much improved mechanical properties under complementary substrateheating. On the other hand, electrons and UV photons can causeindiscriminate dissociation of chemical bonds, which may adverselydegrade the desired physical and electrical properties of the film, suchas loss of hydrophobicity, increased residual film stress, collapse ofpore structure, film densification and increased dielectric constant.Furthermore, low energy curing sources, such as MW curing, can providesignificant improvements mostly in the heat transfer efficiency, but inthe meantime have side effects, such as for example arcing or transistordamage.

Therefore, according to various embodiments, methods for integrating,patterning, treating, curing, and cleaning dielectric layers, includinglow-k dielectric films, on a substrate using EM radiation are disclosed.Referring now to the drawings wherein like reference numerals designatecorresponding parts throughout the several views, FIG. 1 provides a flowchart 1 illustrating a method for integrating a dielectric film on asubstrate according to an embodiment. Furthermore, a pictorial view 20of a method of integrating a dielectric film on a substrate isillustrated in FIG. 2.

The method illustrated in flow chart 1 begins in step 11 (pictorial view21) with preparing a dielectric film 32 on a substrate 30, wherein thedielectric film 32 is a low-k dielectric film having a dielectricconstant less than or equal to a value of 4. Substrate 30 may be asemiconductor, a metallic conductor, or any other substrate to which thedielectric film 32 is to be formed upon.

Dielectric film 32 may have a dielectric constant value (before dryingand/or curing, or after drying and/or curing, or both) less than thedielectric constant of SiO₂, which is about 4 (e.g., the dielectricconstant for thermal silicon dioxide can range from about 3.8 to 3.9).In various embodiments of the invention, the dielectric film 32 may havea dielectric constant (before drying and/or curing, or after dryingand/or curing, or both) of less than about 3.0, a dielectric constant ofless than about 2.5, a dielectric constant of less than about 2.2, or adielectric constant of less than about 1.7.

The dielectric film 32 may be described as a low dielectric constant(low-k) film or an ultra-low-k film. The dielectric film 32 may includeat least one of an organic, inorganic, and inorganic-organic hybridmaterial. Additionally, the dielectric film 32 may be porous ornon-porous.

The dielectric film 32 may, for instance, include a single phase or dualphase porous low-k film that includes a structure-forming material and apore-generating material. The structure-forming material may include anatom, a molecule, or fragment of a molecule that is derived from astructure-forming precursor. The pore-generating material may include anatom, a molecule, or fragment of a molecule that is derived from apore-generating precursor (e.g., porogen). The single phase or dualphase porous low-k film may have a higher dielectric constant prior toremoval of the pore-generating material than following the removal ofthe pore-generating material.

The forming of a single phase porous low-k film may include depositing astructure-forming molecule having a pore-generating molecular side groupweakly bonded to the structure-forming molecule on a surface of asubstrate. For example, a single-phase material may include a siliconoxide-based matrix having terminal organic side groups that inhibitcross-linking during a curing process to create small voids (or pores).Additionally, the forming of a dual phase porous low-k film may includeco-polymerizing a structure-forming molecule and a pore-generatingmolecule on a surface of a substrate. For example, a dual-phase materialmay include a silicon oxide-based matrix having inclusions of organicmaterial (e.g., a porogen) that is decomposed and evaporated during acuring process.

Additionally, the dielectric film 32 may have moisture, water, solvent,and/or other contaminants which cause the dielectric constant to behigher prior to drying and/or curing than following drying and/orcuring.

The dielectric film 32 may be formed using chemical vapor deposition(CVD) techniques, or spin-on dielectric (SOD) techniques such as thoseoffered in the Clean Track ACT 8 SOD and ACT 12 SOD coating systemscommercially available from Tokyo Electron Limited (TEL). The CleanTrack ACT 8 (200 mm) and ACT 12 (300 mm) coating systems provide coat,bake, and cure tools for SOD materials. The track system can beconfigured for processing substrate sizes of 100 mm, 200 mm, 300 mm, andgreater. Other systems and methods for forming a film on a substrate asknown to those skilled in the art of both spin-on dielectric technologyand CVD dielectric technology are suitable for the invention.

In 12 and in pictorial view 22, a preliminary curing process isperformed on dielectric film 32 to at least partially cure dielectricfilm 32 to produce soft-cured dielectric film 32A. The preliminarycuring process may precede any patterning of the dielectric film 32, andmay include a thermal curing process, an infrared (IR) curing process,or an ultraviolet (UV) curing process, or any combination of two or morethereof. Additionally, the preliminary curing process may be performedat a first substrate temperature. As an example, the preliminary curingprocess may cause preliminary cross-linking to assist in relievingstress in the dielectric film 32 during subsequent curing step(s).Furthermore, for example, the preliminary curing process may causereduction in damage incurred during subsequent patterning via etchprocesses and/or cleaning processes.

In one embodiment, the preliminary curing process includes soft-curingthe dielectric film 32 using UV radiation with optional IR radiation andoptional thermal heating.

During the preliminary curing process, the UV exposure may comprise aplurality of UV exposures, wherein each UV exposure may or may notinclude a different intensity, power, power density, exposure times, orwavelength range, or any combination of two or more thereof.Additionally, the IR exposure may comprise a plurality of IR exposures,wherein each IR exposure may or may not include a different intensity,power, power density, exposure times, or wavelength range, or anycombination of two or more thereof. Furthermore, the UV exposure and theIR exposure may be performed either sequentially or in parallel.

During the UV exposure, or the IR exposure, or both, dielectric film 32may be heated by elevating the substrate temperature of substrate 30 tothe first substrate temperature, wherein the first substrate temperatureranges from about 100 degrees C. (Celsius, or Centigrade) to about 600degrees C. Alternatively, the first substrate temperature ranges fromabout 100 degrees C. to about 500 degrees C. Alternatively, the firstsubstrate temperature ranges from about 100 degrees C. to about 300degrees C. Substrate thermal heating may be performed by conductiveheating, convective heating, or radiative heating, or any combination oftwo or more thereof. For example, the substrate temperature may beincreased by elevating the temperature of a substrate holder in contactwith substrate 30.

Additionally, thermal heating of substrate 30 may take place before UVexposure, during UV exposure, or after UV exposure, or any combinationof two or more thereof. Additionally yet, thermal heating may take placebefore IR exposure, during IR exposure, or after IR exposure, or anycombination of two or more thereof. Thermal heating may be performed byconductive heating, convective heating, or radiative heating, or anycombination of two or more thereof.

Prior to UV and/or IR exposure, a drying process may be performed toremove, or partially remove, one or more contaminants in the dielectricfilm 32, including, for example, moisture, water, solvent,pore-generating material, residual pore-generating material,pore-generating molecules, fragments of pore-generating molecules, orany other contaminant that may interfere with the preliminary curingprocess.

The exposure of the dielectric film 32 to UV radiation may includeexposing the dielectric film 32 to UV radiation from one or more UVlamps, one or more UV LEDs (light-emitting diodes), or one or more UVlasers, or a combination of two or more thereof. The UV radiation may becontinuous or pulsed. The UV radiation may be broad band or narrow band.The UV radiation may include UV emission ranging in wavelength fromapproximately 100 nanometers (nm) to approximately 600 nm.Alternatively, the UV radiation may range in wavelength fromapproximately 150 nm to approximately 400 nm. Alternatively, the UVradiation may range in wavelength from approximately 200 nm toapproximately 350 nm. Alternatively, the UV radiation may range inwavelength from approximately 150 nm to approximately 250 nm.Alternatively, the UV radiation may range in wavelength fromapproximately 170 nm to approximately 240 nm. Alternatively, the UVradiation may range in wavelength from approximately 200 nm toapproximately 250 nm.

The exposure of the dielectric film 32 to IR radiation may includeexposing the dielectric film 32 to IR radiation from one or more IRlamps, one or more IR LEDs (light emitting diodes), or one or more IRlasers, or a combination of two or more thereof. The IR radiation may becontinuous or pulsed. The IR radiation may be broad band or narrow band.For example, the IR radiation may contain substantially monochromaticelectromagnetic (EM) radiation having a narrow band of wavelengths. TheIR radiation may include IR emission ranging in wavelength fromapproximately 1 micron to approximately 25 microns. Alternatively, theIR radiation may range in wavelength from approximately 2 microns toapproximately 20 microns. Alternatively, the IR radiation may range inwavelength from approximately 8 microns to approximately 14 microns.Alternatively, the IR radiation may range in wavelength fromapproximately 8 microns to approximately 12 microns. Alternatively, theIR radiation may range in wavelength from approximately 9 microns toapproximately 10 microns.

The inventors have recognized that the energy level (hv) delivered canbe varied during different stages of the preliminary curing process. Thepreliminary curing process may include mechanisms for the removal ofmoisture and/or contaminants, the removal of pore-generating material,the decomposition of pore-generating material, the generation ofcross-linking initiators, the cross-linking of the dielectric film, andthe diffusion of the cross-linking initiators. Each mechanism mayrequire a different energy level and rate at which energy is deliveredto the dielectric film.

For instance, during the removal of pore-generating material, theremoval process may be facilitated by photon absorption at IRwavelengths. The inventors have discovered that IR exposure assists theremoval of pore-generating material more efficiently than thermalheating or UV exposure.

Additionally, for instance, during the removal of pore-generatingmaterial, the removal process may be assisted by decomposition of thepore-generating material. The removal process may include IR exposurethat is complemented by UV exposure. The inventors have discovered thatUV exposure may assist a removal process having IR exposure bydissociating bonds between pore-generating material (e.g.,pore-generating molecules and/or pore-generating molecular fragments)and the structure-forming material. For example, the removal and/ordecomposition processes may be assisted by photon absorption at UVwavelengths (e.g., about 300 nm to about 450 nm).

Furthermore, for instance, during the generation of cross-linkinginitiators, the initiator generation process may be facilitated by usingphoton and phonon induced bond dissociation within the structure-formingmaterial. The inventors have discovered that the initiator generationprocess may be facilitated by UV exposure. For example, bonddissociation can require energy levels having a wavelength less than orequal to approximately 300 to 400 nm.

Further yet, for instance, during cross-linking, the cross-linkingprocess can be facilitated by thermal energy sufficient for bondformation and reorganization. The inventors have discovered thatcross-linking may be facilitated by IR exposure or thermal heating orboth. For example, bond formation and reorganization may require energylevels having a wavelength of approximately 9 microns which, forexample, corresponds to the main absorbance peak in siloxane-basedorganosilicate low-k materials.

In 13 and in pictorial view 23, a pattern is formed in the soft-cureddielectric film 32A using a lithographic process and an etching process.The lithographic process includes preparing the pattern in a layer ofradiation-sensitive material, such as photo-resist, using an imageexposure and developing sequence. For example, the pattern may include atrench or line pattern, or a via or hole pattern, or a combinationthereof. The pattern is transferred to an underlying hard mask layer orcap layer 34 and, thereafter, to the soft-cured dielectric film 32Ausing one or more etch processes. The one or more etch processes mayinclude dry and/or wet etch processes. For example, the one or more etchprocesses may include dry plasma and/or dry non-plasma etch processes.

In 14 and in pictorial view 24, undesired residues, such as surfaceresidue 35, is removed from the substrate 30 to produce reduced residue35A on the exposed surface of soft-cured dielectric film 32A. Theexposed surface having reduced residue 35A may also exhibit reduceddamage. As an example, the undesired residues may include surfaceadsorbates, particulates, moisture, etch residue, undesiredcarbon-containing residue, amorphous carbon-containing residue,hydrocarbon-containing residue, fluorocarbon-containing residue,halogen-containing residue, or polymer-containing residue, or anycombination of two or more thereof.

During the patterning of dielectric film 32, or soft-cured dielectricfilm 32A, including ultra low-k dielectric films (i.e., dielectric filmshaving a dielectric constant k less than or equal to a value of 2.5),the one or more etch processes utilized to perform the patterning ofdielectric film 32 may cause damage to the dielectric film 32, orsoft-cured dielectric film 32A, including degradation of the dielectricconstant k, the surface roughness, and the hydrophilicity of thedielectric film 32, among others. Furthermore, during removal of the oneor more mask layers utilized in the patterning of dielectric film 32, orsoft-cured dielectric film 32A, using an ashing process, such as aplasma ashing process, and/or a wet cleaning process, additionaldegradation and/or damage, including additional accumulation of surfaceadsorbates, may be incurred. Further yet, during the preparation of alow dielectric constant k for dielectric film 30, or soft-cureddielectric film 32A, increased carbon content is desirable. However,when the carbon content is increased using a plasma enhanced chemicalvapor deposition (PECVD) process, unintended amorphous carbon residuewith a relatively high dielectric constant k remains which is difficultto remove. This amorphous carbon-containing residue prevents furtherreduction of the dielectric constant k.

Therefore, the removal of undesired residues may include: (1) strippingone or more mask layers, such as photo-resist or photo-resist residue,utilized during the patterning of dielectric film 32, or soft-cureddielectric film 32A; (2) cleaning one or more exposed surfaces ofdielectric film 32, or soft-cured dielectric film 32A, to remove any ofthe aforementioned undesired residues or surface adsorbates, includingmoisture, etch residue, halogen-containing residue,fluorocarbon-containing residue, hydrocarbon-containing residue, etc.;(3) dehydrating one or more exposed surfaces of dielectric film 32, orsoft-cured dielectric film 32A; (4) reducing the dielectric constant kof dielectric film 32, or soft-cured dielectric film 32A, with theremoval of unintended amorphous carbon-containing residue; or (5)performing one or more stripping and/or cleaning processes withoutdegrading and/or further damaging dielectric film 32, or soft-cureddielectric film 32A, or (6) performing any combination of two or morethereof.

In one embodiment, the undesired residues may be removed using a dry EMradiation cleaning process by irradiating substrate 30 containing thepattern in the dielectric film 32, or soft-cured dielectric film 32A,with IR radiation and optionally UV radiation. As will be discussed ingreater detail below, undesired residues may be removed from substrate30 by irradiating substrate 30 with a beam of IR radiation coupled withan optional exposure to UV radiation and/or an optional exposure to agas or vapor jet emanating from a nozzle along a jet axis in a directiontowards substrate 30, wherein the gas or vapor jet may be reactive ornon-reactive with substrate 30. Furthermore, the removal of undesiredresidues may include heating substrate 30 to a substrate temperatureranging from about 20 degrees C. to about 250 degrees C.

The inventors believe that IR radiation, such as far IR emission, may beabsorbed strongly in the patterned dielectric films, and/or typicalsurface adsorbates, such as hydrocarbon-containing material andfluorocarbon-containing material. Additionally, it is believed that thethermophoretic force resulting from the temperature gradient ensuingfrom EM radiation may assist in the removal of surface adsorbates andparticulates. Furthermore, it is believed that UV radiation may assistin the scission of chemical bonds typical in surface adsorbates, such asphoto-resist, hydrocarbon-containing material, andfluorocarbon-containing material, thus, facilitating the desorptionprocess.

In another embodiment, the undesired residues may be removed using a dryEM radiation cleaning process, as described above, coupled with areduced ashing process, such as a reduced plasma ashing process. Thereduced ashing process may be utilized to remove, at least in part,undesired residues. For example, the reduced ashing process may includea process condition, such as a plasma process condition, that causesreduced damage to the dielectric film 32, or soft-cured dielectric film32A. The process condition may include a reduced ashing time, a reducedplasma power, a reduced chemistry (e.g., less aggressive chemistry, orless damaging chemistry), or any combination thereof.

In yet another embodiment, the undesired residues may be removed usingan ashing process, or a wet cleaning process, or both. For example, theashing process may include a dry plasma ashing process. Additionally,for example, the wet cleaning process may include immersing substrate 30in a wet cleaning solution, such as an aqueous HF solution.

In pictorial view 25, an optional silylation process may be performedfollowing the removing of undesired residues in 14 (pictorial view 24),and preceding a final curing process to produce silylated surface layer35B. The silylation process includes the introduction of a silyl groupto the dielectric film 32, or soft-cured dielectric film 32A, to serveas a protecting group for planarization, healing, and/or sealing of theexposed surface of the dielectric film 32, or soft-cured dielectric film32A.

In one embodiment, the silylation process may include introducing asilane compound, a silazane compound, HMDS, or TMCS, or any combinationof two or more thereof. The silylation may further include maintainingsubstrate 30 at a substrate temperature between about 200 degrees C. andabout 400 degrees C. In another embodiment, the silylation process mayfurther include irradiating substrate 30 with UV radiation.

In 15 and in pictorial view 26, a final curing process is performed ondielectric film 32, or soft-cured dielectric film 32A, to at leastadditionally cure dielectric film 32 to produce hard-cured dielectricfilm 32B. The final curing process may include a thermal curing process,an IR curing process, or a UV curing process, or any combination of twoor more thereof. Additionally, the final curing process may be performedat a second substrate temperature. In one embodiment, the secondsubstrate temperature exceeds the first substrate temperature. As anexample, the final curing process may cause substantially completecross-linking of the dielectric film 32, or soft-cured dielectric film32A, to produce enhanced film properties including, for example,mechanical properties.

In one embodiment, the final curing process includes hard-curing thedielectric film 32 using UV radiation with optional IR radiation andoptional thermal heating.

During the final curing process, the UV exposure may comprise aplurality of UV exposures, wherein each UV exposure may or may notinclude a different intensity, power, power density, exposure times, orwavelength range, or any combination of two or more thereof.Additionally, the IR exposure may comprise a plurality of IR exposures,wherein each IR exposure may or may not include a different intensity,power, power density, exposure times, or wavelength range, or anycombination of two or more thereof. Furthermore, the UV exposure and theIR exposure may be performed either sequentially or in parallel.

During the UV exposure, or the IR exposure, or both, dielectric film 32,or soft-cured dielectric film 32A, may be heated by elevating thesubstrate temperature of substrate 30 to the first substratetemperature, wherein the first substrate temperature ranges fromapproximately 100 degrees C. to approximately 600 degrees C.Alternatively, the first substrate temperature ranges from approximately100 degrees C. to approximately 500 degrees C. Alternatively, the firstsubstrate temperature ranges from approximately 100 degrees C. toapproximately 300 degrees C. Substrate thermal heating may be performedby conductive heating, convective heating, or radiative heating, or anycombination of two or more thereof. For example, the substratetemperature may be increased by elevating the temperature of a substrateholder in contact with substrate 30.

Additionally, thermal heating of substrate 30 may take place before UVexposure, during UV exposure, or after UV exposure, or any combinationof two or more thereof. Additionally yet, thermal heating may take placebefore IR exposure, during IR exposure, or after IR exposure, or anycombination of two or more thereof. Thermal heating may be performed byconductive heating, convective heating, or radiative heating, or anycombination of two or more thereof.

Prior to UV and/or IR exposure, a drying process may be performed toremove, or partially remove, one or more contaminants in the dielectricfilm 32, or the soft-cured dielectric film 32A, including, for example,moisture, water, solvent, pore-generating material, residualpore-generating material, pore-generating molecules, fragments ofpore-generating molecules, or any other contaminant that may interferewith the final curing process.

The exposure of the dielectric film 32, or the soft-cured dielectricfilm 32A, to UV radiation may include exposing the dielectric film 32,or the soft-cured dielectric film 32A, to UV radiation from one or moreUV lamps, one or more UV LEDs (light-emitting diodes), or one or more UVlasers, or a combination of two or more thereof. The UV radiation may becontinuous or pulsed. The UV radiation may be broad band or narrow band.The UV radiation may include UV emission ranging in wavelength fromapproximately 100 nanometers (nm) to approximately 600 nm.Alternatively, the UV radiation may range in wavelength fromapproximately 150 nm to approximately 400 nm. Alternatively, the UVradiation may range in wavelength from approximately 200 nm toapproximately 350 nm. Alternatively, the UV radiation may range inwavelength from approximately 150 nm to approximately 250 nm.Alternatively, the UV radiation may range in wavelength fromapproximately 170 nm to approximately 240 nm. Alternatively, the UVradiation may range in wavelength from approximately 200 nm toapproximately 250 nm.

The exposure of the dielectric film 32, or the soft-cured dielectricfilm 32A, to IR radiation may include exposing the dielectric film 32,or the soft-cured dielectric film 32A, to IR radiation from one or moreIR lamps, one or more IR LEDs (light emitting diodes), or one or more IRlasers, or a combination of two or more thereof. The IR radiation may becontinuous or pulsed. The IR radiation may be broad band or narrow band.For example, the IR radiation may contain substantially monochromaticelectromagnetic (EM) radiation having a narrow band of wavelengths. TheIR radiation may include IR emission ranging in wavelength fromapproximately 1 micron to approximately 25 microns. Alternatively, theIR radiation may range in wavelength from approximately 2 microns toapproximately 20 microns. Alternatively, the IR radiation may range inwavelength from approximately 8 microns to approximately 14 microns.Alternatively, the IR radiation may range in wavelength fromapproximately 8 microns to approximately 12 microns. Alternatively, theIR radiation may range in wavelength from approximately 9 microns toapproximately 10 microns.

The inventors have recognized that the energy level (hv) delivered canbe varied during different stages of the final curing process. The finalcuring process may include mechanisms for the removal of moisture and/orcontaminants, the removal of pore-generating material, the decompositionof pore-generating material, the generation of cross-linking initiators,the cross-linking of the dielectric film, and the diffusion of thecross-linking initiators. Each mechanism may require a different energylevel and rate at which energy is delivered to the dielectric film.

For instance, during the removal of pore-generating material, theremoval process may be facilitated by photon absorption at IRwavelengths. The inventors have discovered that IR exposure assists theremoval of pore-generating material more efficiently than thermalheating or UV exposure.

Additionally, for instance, during the removal of pore-generatingmaterial, the removal process may be assisted by decomposition of thepore-generating material. The removal process may include IR exposurethat is complemented by UV exposure. The inventors have discovered thatUV exposure may assist a removal process having IR exposure bydissociating bonds between pore-generating material (e.g.,pore-generating molecules and/or pore-generating molecular fragments)and the structure-forming material. For example, the removal and/ordecomposition processes may be assisted by photon absorption at UVwavelengths (e.g., about 300 nm to about 450 nm).

Furthermore, for instance, during the generation of cross-linkinginitiators, the initiator generation process may be facilitated by usingphoton and phonon induced bond dissociation within the structure-formingmaterial. The inventors have discovered that the initiator generationprocess may be facilitated by UV exposure. For example, bonddissociation can require energy levels having a wavelength less than orequal to approximately 300 to 400 nm.

Further yet, for instance, during cross-linking, the cross-linkingprocess can be facilitated by thermal energy sufficient for bondformation and reorganization. The inventors have discovered thatcross-linking may be facilitated by IR exposure or thermal heating orboth. For example, bond formation and reorganization may require energylevels having a wavelength of approximately 9 microns which, forexample, corresponds to the main absorbance peak in siloxane-basedorganosilicate low-k materials.

Furthermore, the patterned, hard-cured dielectric film 32B mayoptionally be post-treated in a post-treatment system configured tomodify the hard-cured dielectric film 32B. For example, post-treatmentmay include thermal heating the hard-cured dielectric film 32B.Alternatively, for example, post-treatment may include spin coating orvapor depositing another film on the hard-cured dielectric film 32B inorder to promote adhesion for subsequent films or improvehydrophobicity. Alternatively, for example, adhesion promotion may beachieved in a post-treatment system by lightly bombarding the hard-cureddielectric film 32B with ions. Moreover, the post-treatment may compriseperforming one or more of depositing another film on the hard-cureddielectric film 32B, cleaning the hard-cured dielectric film 32B, orexposing the hard-cured dielectric film 32B to plasma.

Referring now to FIG. 3, a flow chart 4 illustrating a method forcleaning a substrate is provided according to an embodiment.Furthermore, systems and methods for cleaning a substrate areillustrated in FIGS. 4A, 4B, and 5A through 5D.

As illustrated in FIGS. 3, 4A, 4B, and 5A-5D, the method illustrated inflow chart 4 begins in 41 with irradiating a region 62 on a substrate 50containing one or more layers or structures 60A-D with infrared (IR)radiation and optionally ultraviolet (UV) radiation to remove materialor undesired residues 65A-D from the one or more layers or structures60A-D. As an example, the undesired residues may include surfaceadsorbates, particulates, moisture, etch residue, undesiredcarbon-containing residue, amorphous carbon-containing residue,hydrocarbon-containing residue, fluorocarbon-containing residue,halogen-containing residue, or polymer-containing residue, or anycombination of two or more thereof.

The one or more layers or structures 60A-60D may include a low-k layer,an ultra low-k layer, a photo-resist layer, an anti-reflective coating(ARC) layer, an organic planarization layer (OPL), a soft mask layer, ora hard mask layer, or any combination of two or more thereof.Furthermore, the one or more layers or structures 60A-60D may include anun-patterned, blanket layer or structure, or the one or more layers orstructures 60A-60D may include a patterned layer or structure, as shownin FIGS. 5A through 5D. For example, the patterned layer or structuremay be formed using lithographic and/or etching processes. Additionally,for example, the patterned layer or structure may be formed using apatterned mask layer and an etching process.

The IR radiation may include a beam of IR radiation 52 emitted from anIR source 51 yielding a beam spot 53 on substrate 50. The IR source 51may include one or more IR lamps, one or more IR LEDs (light emittingdiodes), or one or more IR lasers, or a combination of two or morethereof. The IR radiation may be continuous or pulsed. The IR radiationmay be broad band or narrow band. For example, the IR radiation maycontain substantially monochromatic electromagnetic (EM) radiationhaving a narrow band of wavelengths. The IR radiation may include IRemission ranging in wavelength from approximately 1 micron toapproximately 25 microns. Alternatively, the IR radiation may range inwavelength from approximately 2 microns to approximately 20 microns.Alternatively, the IR radiation may range in wavelength fromapproximately 8 microns to approximately 14 microns. Alternatively, theIR radiation may range in wavelength from approximately 8 microns toapproximately 12 microns. Alternatively, the IR radiation may range inwavelength from approximately 9 microns to approximately 10 microns. Aspectral content for the IR radiation may be selected to causeabsorption in at least a portion of remnants of the one or more layersor structures 60A-60D, or at least a portion of the material orundesired residues to be removed.

The UV source (not shown) may include one or more UV lamps, one or moreUV LEDs (light-emitting diodes), or one or more UV lasers, or acombination of two or more thereof. The UV radiation may be continuousor pulsed. The UV radiation may be broad band or narrow band. The UVradiation may include UV emission ranging in wavelength fromapproximately 100 nanometers (nm) to approximately 600 nm.Alternatively, the UV radiation may range in wavelength greater thanapproximately 250 nm.

The IR exposure and the UV exposure may be performed either sequentiallyor in parallel. For example, the irradiating may include IR irradiationsimultaneous with UV radiation, preceded by UV radiation, or followed byUV irradiation, or any combination of two or more thereof.

During the IR exposure, or the UV exposure, or both, the one or morelayers or structures 60A-D may be heated by elevating the substratetemperature of substrate 50 to a temperature ranging from approximately20 degrees C. to approximately 250 degrees C. For example, the substratetemperature may be increased by elevating the temperature of a substrateholder in contact with substrate 50.

Additionally, thermal heating of substrate 50 may take place before IRexposure, during IR exposure, or after IR exposure, or any combinationof two or more thereof. Additionally yet, thermal heating may take placebefore UV exposure, during UV exposure, or after UV exposure, or anycombination of two or more thereof. Thermal heating may be performed byconductive heating, convective heating, or radiative heating, or anycombination of two or more thereof.

In 42, at least a portion of region 62 is exposed to a gas or vapor jet(56, 56′) emanating from a gas nozzle 55 along a jet axis (57, 57′) in adirection towards substrate 50. For example, the jet axis (57, 57′) mayintersect with the beam spot 53 on substrate 50. The gas or vapor jet(56, 56′) may be selected to be reactive or non-reactive with at least aportion of region 62. Further, the gas or vapor jet (56, 56′) maycontain He, Ne, Ar, Kr, Xe, N₂, H₂, NH₃, CO, CO₂, or O₂, or anycombination of two or more thereof. For example, oxygen-containing gasesmay combine with carbon to produce volatile byproducts, such as CO orCO₂.

In an example, a cleaning process is schematically illustrated in FIG.5A. The cleaning process includes irradiating one or more layers orstructures 60A containing a patterned low-k dielectric material 63 withIR radiation 67 assisted by UV radiation 68 to remove photo-resist layer64A and photo-resist residue 65A on the sidewalls of patterned low-kdielectric material 63. As a result, the cleaning process produces oneor more cleaned layers or structures 61A having reduced photo-resist 66Aand/or photo-resist related damage. The inventors believe that UVradiation having UV emission greater than about 300 nm (although notlimited to this wavelength range) may selectively graft polymeradsorbates at low substrate temperature, while absorption of IRradiation may assist the desorption of volatile polymer residue onexposed surfaces of the low-k dielectric material. As described above,the cleaning process may be further coupled with a reduced (e.g., lessaggressive) ashing process.

In another example, a cleaning process is schematically illustrated inFIG. 5B. The cleaning process includes irradiating one or more layers orstructures 60B containing a patterned low-k dielectric material 63 andpatterned hard mask/cap material 64B with IR radiation 67 assisted by UVradiation 68 to remove photo-resist residue 65B on the sidewalls ofpatterned low-k dielectric material 63. As a result, the cleaningprocess produces one or more cleaned layers or structures 61B havingreduced photo-resist 66B and/or photo-resist related damage. Theinventors believe that UV radiation having UV emission greater thanabout 300 nm (although not limited to this wavelength range) mayselectively graft polymer adsorbates at low substrate temperature, whileabsorption of IR radiation may assist the desorption of volatile polymerresidue on exposed surfaces of the low-k dielectric material. Asdescribed above, the cleaning process may be further coupled with areduced (e.g., less aggressive) ashing process.

In another example, a cleaning process is schematically illustrated inFIG. 5C. The cleaning process includes irradiating one or more layers orstructures 60C containing a patterned low-k dielectric material 63 andpatterned hard mask/cap material 64C with IR radiation 67 to removemoisture 65C on the sidewalls of patterned low-k dielectric material 63.As a result, the cleaning process produces one or more cleaned layers orstructures 61C having reduced moisture 66C and/or moisture relateddamage. The inventors believe that IR radiation may selectively heat thelow-k dielectric material to remove moisture.

In another example, a cleaning process is schematically illustrated inFIG. 5D. The cleaning process includes irradiating one or more layers orstructures 60D containing a patterned low-k dielectric material 63 andpatterned soft mask/hard mask/cap material 64D with IR radiation 67 toremove amorphous carbon 65D on the sidewalls of patterned low-kdielectric material 63. As a result, the cleaning process produces oneor more cleaned layers or structures 61D having reduced amorphous carbon66D and/or amorphous carbon related damage. Additionally oralternatively, the cleaning process may include UV radiation. Theinventors believe that IR and/or UV radiation may efficiently removeamorphous carbon to reduce dielectric constant k. Furthermore, theinventors believe that subsequent UV-induced silylation is moreeffectively applied following the IR and/or UV exposure in the cleaningprocess.

According to one embodiment, FIGS. 6 and 7 provide a side view and topview, respectively, of a process platform 100 for treating a dielectricfilm on a substrate. The process platform 100 includes a first processmodule 110 and a second process module 120. The first process module 110may include a curing system, a cleaning system, a surface modificationsystem, or a drying system. The second process module 120 may include acuring system, a cleaning system, a surface modification system, or adrying system.

The drying system may be configured to remove, or reduce to sufficientlevels, one or more contaminants, pore-generating materials, and/orcross-linking inhibitors in the dielectric film, including, for example,moisture, water, solvent, contaminants, pore-generating material,residual pore-generating material, a weakly bonded side group to thestructure-forming material, pore-generating molecules, fragments ofpore-generating molecules, cross-linking inhibitors, fragments ofcross-linking inhibitors, or any other contaminant that may interferewith a curing process performed in the curing system.

For example, a sufficient reduction of a specific contaminant presentwithin the dielectric film, from prior to the drying process tofollowing the drying process, can include a reduction of approximately10% to approximately 100% of the specific contaminant. The level ofcontaminant reduction may be measured using Fourier transform infrared(FTIR) spectroscopy, or mass spectroscopy. Alternatively, for example, asufficient reduction of a specific contaminant present within thedielectric film can range from approximately 50% to approximately 100%.Alternatively, for example, a sufficient reduction of a specificcontaminant present within the dielectric film can range fromapproximately 80% to approximately 100%.

Referring still to FIG. 6, the curing system may be configured toperform the preliminary curing process, or the final curing process, orboth. Additionally, the curing system may be configured to cure thedielectric film by causing or partially causing cross-linking within thedielectric film in order to, for example, improve the mechanicalproperties of the dielectric film. Furthermore, the curing system may beconfigured to cure the dielectric film by causing or partially causingcross-link initiation, removal of pore-generating material,decomposition of pore-generating material, etc. The curing system caninclude one or more radiation sources configured to expose the substratehaving the dielectric film to EM radiation at multiple EM wavelengths.For example, the one or more radiation sources can include an IRradiation source and a UV radiation source. The exposure of thesubstrate to UV radiation and IR radiation may be performedsimultaneously, sequentially, or partially over-lapping one another.During sequential exposure, the exposure of the substrate to UVradiation can, for instance, precede the exposure of the substrate to IRradiation or follow the exposure of the substrate to IR radiation orboth. Additionally, during sequential exposure, the exposure of thesubstrate to IR radiation can, for instance, precede the exposure of thesubstrate to UV radiation or follow the exposure of the substrate to UVradiation or both.

For example, the IR radiation can include an IR radiation source rangingfrom approximately 1 micron to approximately 25 microns. Additionally,for example, the IR radiation may range from about 2 microns to about 20microns, or from about 8 microns to about 14 microns, or from about 8microns to about 12 microns, or from about 9 microns to about 10microns. Additionally, for example, the UV radiation can include a UVwave-band source producing radiation ranging from approximately 100nanometers (nm) to approximately 600 nm. Furthermore, for example, theUV radiation may range from about 150 nm to about 400 nm, or from about150 nm to about 300 nm, or from about 170 to about 240 nm, or from about200 nm to about 240 nm.

Alternatively, the first process module 110 may comprise a first curingsystem configured to expose the substrate to UV radiation, and thesecond process module 120 may comprise a second curing system configuredto expose the substrate to IR radiation.

IR exposure of the substrate can be performed in the first processmodule 110, or the second process module 120, or a separate processmodule (not shown).

Referring still to FIG. 6, the cleaning system may be configured toperform the removal of undesired residues. For example, the cleaningsystem may include any one of the systems described in FIGS. 4A and 4B.

Also, as illustrated in FIGS. 6 and 7, a transfer system 130 can becoupled to the second process module 120 in order to transfer substratesinto and out of the first process module 110 and the second processmodule 120, and exchange substrates with a multi-element manufacturingsystem 140. Transfer system 130 may transfer substrates to and from thefirst process module 110 and the second process module 120 whilemaintaining a vacuum environment.

The first and second process modules 110, 120, and the transfer system130 can, for example, include a processing element 102 within themulti-element manufacturing system 140. The transfer system 130 maycomprise a dedicated substrate handler 160 for moving a one or moresubstrates between the first process module 110, the second processmodule 120, and the multi-element manufacturing system 140. For example,the dedicated substrate handler 160 is dedicated to transferring the oneor more substrates between the process modules (first process module 110and second process module 120), and the multi-element manufacturingsystem 140; however, the embodiment is not so limited.

For example, the multi-element manufacturing system 140 may permit thetransfer of substrates to and from processing elements including suchdevices as etch systems, deposition systems, coating systems, patterningsystems, metrology systems, etc. As an example, the deposition systemmay include one or more vapor deposition systems, each of which isconfigured to deposit a dielectric film on a substrate, wherein thedielectric film comprises a porous dielectric film, a non-porousdielectric film, a low dielectric constant (low-k) film, or an ultralow-k film. In order to isolate the processes occurring in the first andsecond systems, an isolation assembly 150 can be utilized to couple eachsystem. For instance, the isolation assembly 150 can include at leastone of a thermal insulation assembly to provide thermal isolation, and agate valve assembly to provide vacuum isolation. The first and secondprocess modules 110 and 120, and transfer system 130 can be placed inany sequence.

FIG. 7 presents a top-view of the process platform 100 illustrated inFIG. 6 for processing one or more substrates. In this embodiment, asubstrate 142 is processed in the first and second process modules 110,120. Although only one substrate is shown in each treatment system inFIG. 7, two or more substrates may be processed in parallel in eachprocess module.

Referring still to FIG. 7, the process platform 100 may comprise a firstprocess element 102 and a second process element 104 configured toextend from the multi-element manufacturing system 140 and work inparallel with one another. As illustrated in FIGS. 6 and 7, the firstprocess element 102 may comprise first process module 110 and secondprocess module 120, wherein a transfer system 130 utilizes the dedicatedsubstrate handler 160 to move substrate 142 into and out of the firstprocess element 102.

Alternatively, FIG. 8 presents a side-view of a process platform 200 forprocessing one or more substrates according to another embodiment.Process platform 200 may be configured for treating a dielectric film ona substrate.

The process platform 200 comprises a first process module 210, and asecond process module 220, wherein the first process module 210 isstacked atop the second process module 220 in a vertical direction asshown. The first process module 210 may comprise a curing system, andthe second process module 220 may comprise a drying system.Alternatively, the first process module 210 may comprise a first curingsystem configured to expose the substrate to UV radiation, and thesecond process module 220 may comprise a second curing system configuredto expose the substrate to IR radiation.

Also, as illustrated in FIG. 8, a transfer system 230 may be coupled tothe first process module 210, in order to transfer substrates into andout of the first process module 210, and coupled to the second processmodule 220, in order to transfer substrates into and out of the secondprocess module 220. The transfer system 230 may comprise a dedicatedhandler 260 for moving one or more substrates between the first processmodule 210, the second process module 220 and the multi-elementmanufacturing system 240. The handler 260 may be dedicated totransferring the substrates between the process modules (first processmodule 210 and second process module 220) and the multi-elementmanufacturing system 240; however, the embodiment is not so limited.

Additionally, transfer system 230 may exchange substrates with one ormore substrate cassettes (not shown). Although only two process modulesare illustrated in FIG. 8, other process modules can access transfersystem 230 or multi-element manufacturing system 240 including suchdevices as etch systems, deposition systems, coating systems, patterningsystems, metrology systems, etc. As an example, the deposition systemmay include one or more vapor deposition systems, each of which isconfigured to deposit a dielectric film on a substrate, wherein thedielectric film comprises a porous dielectric film, a non-porousdielectric film, a low dielectric constant (low-k) film, or an ultralow-k film. An isolation assembly 250 can be used to couple each processmodule in order to isolate the processes occurring in the first andsecond process modules. For instance, the isolation assembly 250 maycomprise at least one of a thermal insulation assembly to providethermal isolation, and a gate valve assembly to provide vacuumisolation. Additionally, for example, the transfer system 230 can serveas part of the isolation assembly 250.

According to another embodiment, FIG. 9 presents a top view of a processplatform 300 for processing a plurality of substrates 342. Processplatform 300 may be configured for treating a dielectric film on asubstrate. The process platform 300 comprises a first process module310, a second process module 320, and an optional auxiliary processmodule 370 coupled to a first transfer system 330 and an optional secondtransfer system 330′. The first process module 310 may comprise a curingsystem, and the second process module 320 may comprise a drying system.Alternatively, the first process module 310 may comprise a first curingsystem configured to expose the substrate 342 to UV radiation, and thesecond process module 320 may comprise a second curing system configuredto expose the substrate 342 to IR radiation.

Also, as illustrated in FIG. 9, the first transfer system 330 and theoptional second transfer system 330′ are coupled to the first processmodule 310 and the second process module 320, and configured to transferone or more substrates 342 in and out of the first process module 310and the second process module 320, and also to exchange one or moresubstrates 342 with a multi-element manufacturing system 340. Themulti-element manufacturing system 340 may comprise a load-lock elementto allow cassettes of substrates 342 to cycle between ambient conditionsand low pressure conditions.

The first and second treatment systems 310, 320, and the first andoptional second transfer systems 330, 330′ can, for example, comprise aprocessing element within the multi-element manufacturing system 340.The transfer system 330 may comprise a first dedicated handler 360 andthe optional second transfer system 330′ comprises an optional seconddedicated handler 360′ for moving one or more substrates 342 between thefirst process module 310, the second process module 320, the optionalauxiliary process module 370 and the multi-element manufacturing system340.

In one embodiment, the multi-element manufacturing system 340 may permitthe transfer of substrates 342 to and from processing elements includingsuch devices as etch systems, deposition systems, coating systems,patterning systems, metrology systems, etc. Furthermore, themulti-element manufacturing system 340 may permit the transfer ofsubstrates 342 to and from the auxiliary process module 370, wherein theauxiliary process module 370 may include an etch system, a depositionsystem, a coating system, a patterning system, a metrology system, etc.As an example, the deposition system may include one or more vapordeposition systems, each of which is configured to deposit a dielectricfilm on a substrate 342, wherein the dielectric film comprises a porousdielectric film, a non-porous dielectric film, a low dielectric constant(low-k) film, or an ultra low-k film.

In order to isolate the processes occurring in the first and secondprocess modules, an isolation assembly 350 is utilized to couple eachprocess module. For instance, the isolation assembly 350 may comprise atleast one of a thermal insulation assembly to provide thermal isolationand a gate valve assembly to provide vacuum isolation. Of course,process modules 310 and 320, and transfer systems 330 and 330′ may beplaced in any sequence.

Referring now to FIG. 10, a process module 400 configured to treat adielectric film on a substrate is shown according to another embodiment.As an example, the process module 400 may be configured to cure adielectric film. As another example, the process module 400 may beconfigured to clean a dielectric film. As yet another example, theprocess module 400 may be configured to modify a surface on a dielectricfilm. Process module 400 includes a process chamber 410 configured toproduce a clean, contaminant-free environment for curing, cleaning,and/or modifying a substrate 425 resting on substrate holder 420.Process module 400 further includes a radiation source 440 configured toexpose substrate 425 having the dielectric film to EM radiation.

The EM radiation is dedicated to a specific radiation wave-band, andincludes single, multiple, narrow band, or broad band EM wavelengthswithin that specific radiation wave-band. For example, the radiationsource 440 can include an IR radiation source configured to produce EMradiation in the IR spectrum. Alternatively, for example, the radiationsource 440 can include a UV radiation source configured to produce EMradiation in the UV spectrum. In this embodiment, IR treatment and UVtreatment of substrate 425 can be performed in a separate processmodules.

The IR radiation source may include a broad band IR source (e.g.,polychromatic), or may include a narrow band IR source (e.g.,monochromatic). The IR radiation source may include one or more IRlamps, one or more IR LEDs, or one or more IR lasers (continuous wave(CW), tunable, or pulsed), or any combination thereof. The IR powerdensity may range up to about 20 W/cm². For example, the IR powerdensity may range from about 1 W/cm² to about 20 W/cm².

Depending on the application, the IR radiation wavelength may range fromapproximately 1 micron to approximately 25 microns. Alternatively, theIR radiation wavelength may range from approximately 8 microns toapproximately 14 microns. Alternatively, the IR radiation wavelength mayrange from approximately 8 microns to approximately 12 microns.Alternatively, the IR radiation wavelength may range from approximately9 microns to approximately 10 microns. For example, the IR radiationsource may include a CO₂ laser system. Additional, for example, the IRradiation source may include an IR element, such as a ceramic element orsilicon carbide element, having a spectral output ranging fromapproximately 1 micron to approximately 25 microns, or the IR radiationsource can include a semiconductor laser (diode), or ion, Ti:sapphire,or dye laser with optical parametric amplification.

The UV radiation source may include a broad band UV source (e.g.,polychromatic), or may include a narrow band UV source (e.g.,monochromatic). The UV radiation source may include one or more UVlamps, one or more UV LEDs, or one or more UV lasers (continuous wave(CW), tunable, or pulsed), or any combination thereof. UV radiation maybe generated, for instance, from a microwave source, an arc discharge, adielectric barrier discharge, or electron impact generation. The UVpower density may range from approximately 0.1 mW/cm² to approximately2000 mW/cm².

Depending on the application, the UV wavelength may range fromapproximately 100 nanometers (nm) to approximately 600 nm.Alternatively, the UV radiation may range from approximately 150 nm toapproximately 400 nm. Alternatively, the UV radiation may range fromapproximately 150 nm to approximately 300 nm. Alternatively, the UVradiation may range from approximately 170 nm to approximately 240 nm.Alternatively, the UV radiation may range from approximately 200 nm toapproximately 350 nm. Alternatively, the UV radiation may range fromapproximately 200 nm to approximately 240 nm. For example, the UVradiation source may include a direct current (DC) or pulsed lamp, suchas a Deuterium (D₂) lamp, having a spectral output ranging fromapproximately 180 nm to approximately 500 nm, or the UV radiation sourcemay include a semiconductor laser (diode), (nitrogen) gas laser,frequency-tripled (or quadrupled) Nd:YAG laser, or copper vapor laser.

The IR radiation source, or the UV radiation source, or both, mayinclude any number of optical devices to adjust one or more propertiesof the output radiation. For example, each source may further includeoptical filters, optical lenses, beam expanders, beam collimators, etc.Such optical manipulation devices as known to those skilled in the artof optics and EM wave propagation are suitable for the invention.

The substrate holder 420 can further include a temperature controlsystem that can be configured to elevate and/or control the temperatureof substrate 425. The temperature control system can be a part of athermal treatment device 430. The substrate holder 420 can include oneor more conductive heating elements embedded in substrate holder 420coupled to a power source and a temperature controller. For example,each heating element can include a resistive heating element coupled toa power source configured to supply electrical power. The substrateholder 420 could optionally include one or more radiative heatingelements. Depending on the application, the temperature of substrate 425can, for example, range from approximately 20 degrees C. toapproximately 600 degrees C., and desirably, the temperature may rangefrom approximately 100 degrees C. to approximately 600 degrees C. Forexample, the temperature of substrate 425 can range from approximately300 degrees C. to approximately 500 degrees C., or from approximately300 degrees C. to approximately 450 degrees C. Alternatively, forexample, the temperature of substrate 425 can range from approximately20 degrees C. to approximately 300 degrees C., or from approximately 20degrees C. to approximately 250 degrees C.

The substrate holder 420 can further include a drive system 435configured to translate, or rotate, or both translate and rotate thesubstrate holder 420 to move the substrate 425 relative to radiationsource 440.

Additionally, the substrate holder 420 may or may not be configured toclamp substrate 425. For instance, substrate holder 420 may beconfigured to mechanically or electrically clamp substrate 425.

Although not shown, substrate holder 420 may be configured to support aplurality of substrates.

Referring again to FIG. 10, process module 400 can further include a gasinjection system 450 coupled to the process chamber 410 and configuredto introduce a purge gas or process gas that is either reactive ornon-reactive with substrate 425 to process chamber 410. The gasinjection system 450 may include a gas nozzle 452 configured to producea gas or vapor jet 454 along a jet axis in a direction towards substrate425. The gas or vapor jet 454 may be simultaneous with and/orintersecting with EM radiation 442 from radiation source 440. The purgegas or process gas may, for example, include an inert gas, such as anoble gas or nitrogen. Alternatively, the purge gas can include othergases listed above, such as for example O₂, H₂, NH₃, C_(x)H_(y), or anycombination thereof. Additionally, process module 400 can furtherinclude a vacuum pumping system 455 coupled to process chamber 410 andconfigured to evacuate the process chamber 410. During a curing process,substrate 425 can be subject to a purge gas environment with or withoutvacuum conditions.

Furthermore, as shown in FIG. 10, process module 400 can include acontroller 460 coupled to process chamber 410, substrate holder 420,thermal treatment device 430, drive system 435, radiation source 440,gas injection system 450, and vacuum pumping system 455. Controller 460includes a microprocessor, a memory, and a digital I/O port capable ofgenerating control voltages sufficient to communicate and activateinputs to the process module 400 as well as monitor outputs from theprocess module 400. A program stored in the memory is utilized tointeract with the process module 400 according to a stored processrecipe. The controller 460 can be used to configure any number ofprocessing elements (410, 420, 430, 435, 440, 450, or 455), and thecontroller 460 can collect, provide, process, store, and display datafrom processing elements. The controller 460 can include a number ofapplications for controlling one or more of the processing elements. Forexample, controller 460 can include a graphic user interface (GUI)component (not shown) that can provide easy to use interfaces thatenable a user to monitor and/or control one or more processing elements.

Referring now to FIG. 11, a process module 500 configured to treat adielectric film on a substrate is shown according to another embodiment.As an example, the process module 500 may be configured to cure adielectric film. As another example, the process module 400 may beconfigured to clean a dielectric film. As yet another example, theprocess module 400 may be configured to modify a surface on a dielectricfilm. Process module 500 includes many of the same elements as thosedepicted in FIG. 10. The process module 500 comprises process chamber410 configured to produce a clean, contaminant-free environment forcuring a substrate 425 resting on substrate holder 420. Process module500 includes a first radiation source 540 configured to expose substrate425 having the dielectric film to a first radiation source grouping ofEM radiation.

Process module 500 further includes a second radiation source 545configured to expose substrate 425 having the dielectric film to asecond radiation source grouping of EM radiation. Each grouping of EMradiation is dedicated to a specific radiation wave-band, and includessingle, multiple, narrow-band, or broadband EM wavelengths within thatspecific radiation wave-band. For example, the first radiation source540 can include an IR radiation source configured to produce EMradiation in the IR spectrum. Additionally, for example, the secondradiation source 545 can include a UV radiation source configured toproduce EM radiation in the UV spectrum. In this embodiment, IRtreatment and UV treatment of substrate 425 can be performed in a singleprocess module.

Additionally, the gas or vapor jet 454 may be simultaneous with and/orintersecting with first EM radiation 542 from first radiation source 540and/or second EM radiation 547 from second radiation source 545.

Furthermore, as shown in FIG. 11, process module 500 can include acontroller 560 coupled to process chamber 410, substrate holder 420,thermal treatment device 430, drive system 435, first radiation source540, second radiation source 545, gas injection system 450, and vacuumpumping system 455. Controller 560 includes a microprocessor, a memory,and a digital I/O port capable of generating control voltages sufficientto communicate and activate inputs to the process module 500 as well asmonitor outputs from the process module 500. A program stored in thememory is utilized to interact with the process module 500 according toa stored process recipe. The controller 560 can be used to configure anynumber of processing elements (410, 420, 430, 435, 540, 545, 450, or455), and the controller 560 can collect, provide, process, store, anddisplay data from processing elements. The controller 460 can include anumber of applications for controlling one or more of the processingelements. For example, controller 560 can include a graphic userinterface (GUI) component (not shown) that can provide easy to useinterfaces that enable a user to monitor and/or control one or moreprocessing elements.

Various assemblies of EM radiation sources and optical systems thereofmay be found in pending U.S. patent application Ser. No. 12/211,598,entitled “DIELECTRIC TREATMENT SYSTEM AND METHOD OF OPERATING”, filed onSep. 16, 2008, and published as U.S. Patent Application Publication No.2010/0065758; the entire content of which is herein incorporated byreference.

Referring now to FIG. 12, a schematic illustration of a process module1200 is presented according to an embodiment. The process module 1200includes a process chamber 1210 configured to produce a clean,contaminant-free environment for curing, cleaning, and/or modifying asubstrate 1225 resting on substrate holder 1220. Process module 1200further includes a radiation source 1230 configured to expose substrate1225 to EM radiation.

The radiation source 1230 includes a UV lamp 1240, and a reflector 1250for directing UV radiation 1242 from the UV lamp 1240 to substrate 1225.Alternatively, the radiation source 1230 may include an IR lamp. Thereflector 1250 has a dichroic reflector 1254, and a non-absorbingreflector 1252 disposed between the UV lamp 1240 and substrate 1225. Thenon-absorbing reflector 1252 is configured to reflect UV radiation 1242from the UV lamp 1240 towards the dichroic reflector 1254, wherein thenon-absorbing reflector 1252 substantially prevents direct UV radiation1244 from the UV lamp 1240 to substrate 1225. The dichroic reflector1254 may be utilized to select at least a portion of the UV radiationspectrum emitted by the UV lamp 1240. For example, radiation source 1230may be configured to irradiate substrate 1225 with UV radiationcontaining emission ranging from about 250 nm to about 450 nm, or about200 nm to about 300 nm, or about 200 nm to about 290 nm, depending onthe type of dichroic coating. The dichroic coating may include one ormore dielectric layers.

Filtering by reflection on a dichroic coating usually does not affectthe original forward rays emitted directly from the UV lamp.Consequently, a typical UV lamp using dichroic reflector still emits asignificant amount of emission outside of the desired wavelength range,causing overheating of the substrate and inefficient porogen removal.The inventors propose to use a second reflection on reflectors withdichroic coating in order to obtain the desired emission spectrum.

In one embodiment, the non-absorbing reflector 1252 is separate from theUV lamp 1240, as shown in FIG. 11. In another embodiment, thenon-absorbing reflector 1252 includes a coating applied to an undersideof the UV lamp 1240.

The non-absorbing reflector 1252 may include a concave reflectingsurface oriented to face a concave reflecting surface of the dichroicreflector 1254, and the non-absorbing reflector 1252 may be positionedbetween the dichroic reflector 1254 and the substrate 1225.Additionally, an apex and a focus of the concave reflecting surface ofthe non-absorbing reflector 1252, and an apex and a focus of the concavereflecting surface of the dichroic reflector 1254 may be collinear.Furthermore, the non-absorbing reflector 1252 and/or the dichroicreflector 1254 may include a cylindrical or spherical geometry having acircular, an elliptical, a parabolic, or a hyperbolic cross-section. Theshape, orientation, and/or position of the non-absorbing reflector 1252and/or the dichroic reflector 1254 may be adjusted to provide optimalirradiation of substrate 1225.

The process module 1200 may include a UV window 1260 disposed betweenthe reflector 1250 and the substrate 1225.

The process module 1200 may further include an IR source, such as an IRsource that provides substantially monochromatic EM radiation having anarrow band of wavelengths, or an IR laser. Additionally, the processmodule 1200 may further include a temperature control system coupled tothe substrate holder 1220 and configured to control a temperature of thesubstrate 1225. Additionally, the process module 1200 may furtherinclude a drive system 1212 coupled to the substrate holder 1220, andconfigured to translate, or rotate, or both translate and rotate thesubstrate holder 1220. Additionally yet, the process module 1200 mayfurther include a gas supply system coupled to the process chamber 1210,and configured to introduce a purge gas and/or process gas to theprocess chamber 1210. For example, the gas supply system may include anozzle configured to produce a gas or vapor jet emanating from thenozzle along a jet axis in a direction towards substrate 1225.

Referring now to FIG. 13, a schematic illustration of a process module1300 is presented according to an embodiment. The process module 1300includes a process chamber 1310 configured to produce a clean,contaminant-free environment for curing, cleaning, and/or modifying asubstrate 1325 resting on substrate holder 1320. Process module 1300further includes a radiation source 1330 configured to expose substrate1325 to EM radiation.

The radiation source 1330 includes a UV lamp 1340, and a reflector 1350for directing UV radiation 1342 from the UV lamp 1340 to substrate 1325.Alternatively, the radiation source 1330 may include an IR lamp. Thereflector 1350 has a dichroic reflector 1354, and a non-absorbingreflector 1352 disposed between the UV lamp 1340 and substrate 1325. Thenon-absorbing reflector 1352 is configured to reflect UV radiation 1342from the UV lamp 1340 towards the dichroic reflector 1354, wherein thenon-absorbing reflector 1352 substantially prevents direct UV radiation1244 from the UV lamp 1340 to substrate 1325. The dichroic reflector1354 may be utilized to select at least a portion of the UV radiationspectrum emitted by the UV lamp 1340. For example, radiation source 1330may be configured to irradiate substrate 1325 with UV radiationcontaining emission ranging from about 250 nm to about 450 nm, or about200 nm to about 300 nm, or about 200 nm to about 290 nm, depending onthe type of dichroic coating. The dichroic coating may include one ormore dielectric layers.

As shown in FIG. 12, the dichroic reflector 1354 comprises a pluralityof dichroic reflecting elements arranged in a first plane 1361 parallelwith substrate 1325 and located above substrate 1325, and thenon-absorbing reflector 1252 comprises a plurality of non-absorbingreflecting elements arranged in a second plane 1362 parallel withsubstrate 1325 and located above substrate 1325 and below the firstplane 1361. Further, the plurality of non-absorbing reflecting elementsand the plurality of dichroic reflecting elements are arranged as pairssuch that a one-to-one relationship exists between each of the pluralityof non-absorbing reflecting elements and each of the plurality ofdichroic reflecting elements.

The non-absorbing reflector 1352 may include a concave reflectingsurface oriented to face a concave reflecting surface of the dichroicreflector 1354, and the non-absorbing reflector 1352 may be positionedbetween the dichroic reflector 1354 and the substrate 1325. The processmodule 1300 may include a UV window 1360 disposed between the reflector1350 and the UV lamp 1340.

The shape, orientation, and/or position of the non-absorbing reflector1352 and/or the dichroic reflector 1354 may be adjusted to provideoptimal irradiation of substrate 1325.

The process module 1300 may further include an IR source, such as an IRsource that provides substantially monochromatic EM radiation having anarrow band of wavelengths, or an IR laser. Additionally, the processmodule 1300 may further include a temperature control system coupled tothe substrate holder 1320 and configured to control a temperature of thesubstrate 1325. Additionally, the process module 1300 may furtherinclude a drive system 1312 coupled to the substrate holder 1320, andconfigured to translate, or rotate, or both translate and rotate thesubstrate holder 1320. Additionally yet, the process module 1300 mayfurther include a gas supply system coupled to the process chamber 1310,and configured to introduce a purge gas and/or process gas to theprocess chamber 1310. For example, the gas supply system may include anozzle configured to produce a gas or vapor jet emanating from thenozzle along a jet axis in a direction towards substrate 1325.

Although only certain exemplary embodiments of this invention have beendescribed in detail above, those skilled in the art will readilyappreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention.

1. A process module for treating a dielectric film on a substrate,comprising: a process chamber; a substrate holder coupled to saidprocess chamber and configured to support a substrate; and a radiationsource coupled to said process chamber and configured to expose saiddielectric film to electromagnetic (EM) radiation, wherein saidradiation source comprises an ultraviolet (UV) source, said UV sourcecomprising: a UV lamp, and a reflector for directing reflected UVradiation from said UV lamp to said substrate, said reflector having adichroic reflector, and a non-absorbing reflector disposed between saidUV lamp and said substrate and configured to reflect UV radiation fromsaid UV lamp towards said dichroic reflector, wherein said non-absorbingreflector substantially prevents direct UV radiation from said UV lampto said substrate.
 2. The process module of claim 1, wherein saidsubstrate is exposed to said reflected UV radiation comprising emissionwavelengths ranging from about 200 nm (nanometers) to about 290 nm. 3.The process module of claim 1, wherein said non-absorbing reflector isseparate from said UV lamp.
 4. The process module of claim 1, whereinsaid non-absorbing reflector comprises a coating applied to an undersideof said UV lamp.
 5. The process module of claim 1, wherein saidnon-absorbing reflector comprises a concave reflecting surface orientedto face at least one concave reflecting surface of said dichroicreflector.
 6. The process module of claim 5, wherein said non-absorbingreflector is positioned between said dichroic reflector and saidsubstrate.
 7. The process module of claim 5, wherein a first apex and afirst focus of said concave reflecting surface of said non-absorbingreflector, and a second apex and a second focus of said concavereflecting surface of said dichroic reflector are collinear.
 8. Theprocess module of claim 1, wherein said dichroic reflector comprises acylindrical or spherical geometry having a circular, an elliptical, aparabolic, or a hyperbolic cross-section.
 9. The process module of claim1, wherein said non-absorbing reflector comprises a cylindrical orspherical geometry having a circular, an elliptical, a parabolic, or ahyperbolic cross-section.
 10. The process module of claim 1, whereinsaid dichroic reflector comprises a plurality of dichroic reflectingelements arranged in a first plane parallel with said substrate andlocated above said substrate, and wherein said non-absorbing reflectorcomprises a plurality of non-absorbing reflecting elements arranged in asecond plane parallel with said substrate and located above saidsubstrate and below said first plane.
 11. The process module of claim10, wherein said plurality of non-absorbing reflecting elements and saidplurality of dichroic reflecting elements are arranged as pairs, whereina one-to-one relationship exists between each of said non-absorbingreflecting elements and each of said dichroic reflecting elements. 12.The process module of claim 1, wherein said radiation source furthercomprises a UV window disposed between said reflector and saidsubstrate.
 13. The process module of claim 1, wherein said radiationsource further comprises a UV window disposed between said reflector andsaid UV lamp.
 14. The process module of claim 1, wherein said radiationsource further comprises an infrared (IR) source.
 15. The process moduleof claim 14, wherein said IR source provides substantially monochromaticelectromagnetic (EM) radiation having a narrow band of wavelengths. 16.The process module of claim 14, wherein said IR source comprises an IRlaser.
 17. The process module of claim 1, further comprising: atemperature control system coupled to said substrate holder andconfigured to control a temperature of said substrate.
 18. The processmodule of claim 1, further comprising: a drive system coupled to saidsubstrate holder, and configured to translate, or rotate, or bothtranslate and rotate said substrate holder.
 19. The process module ofclaim 1, further comprising: a gas supply system coupled to said processchamber, and configured to introduce a process gas to said processchamber.
 20. The process module of claim 19, wherein said gas supplysystem includes a nozzle configured to produce a gas or vapor jetemanating from said nozzle along a jet axis in a direction towards saidsubstrate.